This invention relates to a binding machine which operates to close the mouth of a synthetic resin bag (or net bag) in which pieces of bread, candy or the like have been put.
A bag mouth binding machine has been disclosed by Examined Japanese Patent Publication No. Sho. 63-62416/1988 which uses a flat string of polyvinyl chloride with a thin iron wire as its core to close the mouth of a bag containing pieces of bread, candy or the like. The binding machine has a folding pawl which feeds the flat binding string, in which a core wire such as a metal wire has been buried, as much as a predetermined length, and cuts it and lays it over the mouth of the bag, and turns while catching the end of the flat binding string. More specifically, the binding machine is designed as follows: A flat frame having a bag mouth guide groove at the front end is made up of a pair of side walls, a driving main shaft is provided at the base end which is in alignment with the axial line of the bag mouth guide groove, and a string twisting intermittent gear having a power source releasing arcuate cam on its one side and a string twisting intermittent face gear are provided in front of the driving main shaft. In addition, in the binding machine, a pinion provided at the base end of an orthogonal spindle having a holding pawl at the top end is engaged with the string twisting intermittent face gear, a cam for a string winding arm is integrally provided behind the driving main shaft, a driven lever extended downwardly is swingably provided at the position to which the cam is intermittently turned, a rocking arm is pivotally mounted on the shaft of the driven lever which has a front end winding movable pawl at the front end and an after-motion regulating movable pawl at the middle. Furthermore, in the binding machine, a transmission gear having a resting arcuate portion formed by cutting it is engaged with a string feeding intermittent gear, the resting arcuate portion is so arranged as to slide on the power source releasing arcuate cam, and one of a pair of frictional wheels is mounted on the shaft of the transmission gear.
A binding piece for binding the mouth of synthetic resin bag, such as a bag of polyvinyl chloride, in such a manner that the mouth is puckered, has been disclosed, for instance, by U.S. Pat. Ser. No. 3,021,354. The binding piece has an opening in which the mouth of a bag to be bound is inserted, and a slit through which the puckered mouth of a bag is moved so as to be set in the opening, and prickles or protrusions extended from the edge of the opening towards the center of the latter.
The binding machine disclosed by Japanese Patent Application Publication No. 63-62416/1988 uses the binding string whose core wire is the metal wire as is described above. Hence, the person who has purchased the article wrapped with the bag thus bound, may hurt the fingers with the binding string depending on the way he handles it. In addition, in the case where the article in the bag is heavy, the binding force of the binding string may not be great enough to keep the mouth of the bag closed.